Phonograph attachment



D. McNEILL.

PHONOGRAPH ATTACHMENT.

APPLICATION FILED JAN. 23, 1919.

1,341,51 1 Patented May 25, 1920.

2 SHEETS-SHEET I.

STATES DEITHIW MONEILL, OF HUNTINGTDN, WEST VIRGINIA.

PEONOGRAPH ATTACHMENT.

esitant Specification of Letters Patent.

Patented May 25, 1920.

Application filed January 23, 1919. Serial No. 272,692.

To all, whom it may concern:

Be it known that I, DENNIS MoNnnm, a citizen of the United States, and a resident of Huntington, in the county of Cabell and State of West Virginia, have invented a new and Improved Phonograph Attachment, of which the following is a full, clear, and exact description.

My invention relates to phonographs, my particular purpose being to suppress as far as practicable the undesirable noises due to the mechanical scratching of the stylus upon the record disk or member equivalent thereto.

It is a fact not generally known in this art that the stylus needle by its engagement with the traveling disk or equivalent member forces the diaphragm to-make vibrations independent of the normal or contemplated action of the record disk, or, in other words, causes the diaphragm to so vibrate as to throw off sounds independent of the sounds contemplated by the record considered as a sound producing element. The undesirable sounds thus set up are for the most part in the nature of continuous hisses. While, of course, these undesirable sounds are produced by undulatory movements of the diaphragm, and these undulatory movements are, of course, necessarily and inherently irregular, experlence shows that the undesirable sounds in question tend to resolve themselves into sound waves having more or less symmetry and producingv a tone or note, which though composite, may not perhaps be considered as having a definite itch. p What I seek to do by my invention is to divide the sounds as they pass from the diaphragm through the tone arm and into the horn, and to cause a portion of these sounds to interfere with another portion thereof so as to produce virtually silence,'as regards the piarticular notes or tones above discussc As the receiver used upon a disk machine is gradually shifted or drawn inwardly during the operation of the machine, the tone or note incidentally produced as above described tends to become lower. This is be cause the various little microsco ic bumps, pits and abrasions oi various kinds strlke the stylus with comparatively high fre quency when the portion of the record dick in engagement with the stylus is traveling quite rapidly, and that they strike the stylus with less frequency as the stylus is shifted inwardly toward the center of the disk where the speed of rotation of the disk is slower.

I therefore seek by my invention to divide the sound waves into two parallel channels so arranged as to cause the undesirable sounds passing through one channel to interfere with those passing through the other channel, and thus produce virtual silence. I also seek to vary the length of one of these channels, gradually, during the operation of the machine, so as to cause the sounds passing through it to travel a distance slightly longer than the sounds passing through the other channel, and by doing this I seek to cause the interference of the sound Waves, in passing through the two channelsrto neutralize to a considerable extent the acoustical efi'ect of the two groups of sound waves, and that, too, independently of the fact that the wave lengths of the sounds in question grow longer as the stylus approaches the center of the disk. 7

Reference is. made to the accompanying drawing, forming apart of this specification, in which like characters indicate like parts in all the views.

Figure 1 is a plan view of a phonograph equipped with my attachment, certain parts being broken away;

Fig. 2 is a side view of the same partlyfin elevation and partly in section; and

Fig. 3 is an enlarged section on line 3--3 of Fig. 2 looking in the direction of the arrows.

A phonograph cabinet is shown at 4 and is provided with a lid 5 mounted thereupon by aid of hinges 6. A turntable is shown at 7 anda brake for the turntableat 8, these partsbeing of the usual or any desired con struction. The platform of the machine a pears at 9 and is just below the turntab'e. Resting upon the turntable is a record disk 10, which is provided in the conventional manner with an annular space 11 occupied by sound grooves. At 11, 12 are the respective outer and inner boundary circles of this annular space. The turntable carries a center pin 14 which'extends through the disk.

The cabinet is provided with a slot 15 to accommodate movements of {the horn 16 which extends through the slot, as may be understood from the movable horn 16 is a tone arm 17,1011 in cated as shown more particularly in Fig 1,

Fig. 2. Mounted 'u on This tone arm is provided with a down-. turned portion l7 supporting a reproducer 18. The construction of the tone arm can be readily understood from Figs. 1 and 2. A tubular member 17 is curved slightly, as shown in Fig. 1, and is provided with two reverting neck portions 17 17 A tubular section 17 of soft rubber is fitted over the neck 17 and'is also fitted over the end of a telescopic tubular member 17" which fits over the reverting neck portion 17. The tubular member 17 is so arranged that it maybe slid longitudinally of the neck portion 17, the tubular section 17, because of its flexibility and resilience, being thus adapted to permit this movement. In this manner the tone arm 17 may be considered as bifurcated, that is, made up of two hollow tubular members, one having a fixed length and the other having a variable length, due to constructive variations in the length of the member of which the tubular section17 is a part. The reproducer 18 is provided with a weight 19 and with a connection20. for supporting this weight. The reproducer carries. a stylus 21 adapted for engagement with the face of the record disk 10. Secured rigidly upon the stationary platform 9 is a rack 22 of arcuate form, and engaging this rack is a gear pinion 23 so arranged as to turn slowly as the horn 16 is moved back and forth through the slot 15. The gear 23 is mounted rigidly upon a shaft 24 which extends through bearings 25, 26, these hearings being integral with a bracket 27. The bracket is provided with a collar 28 which encircles the upper portion of the horn 16 and is detachably secured in position thereupon by aid of clamping bolts 29. The shaft 24 carries a bevel pinion '30 fixed upon it, and engaging this bevel pinion is .another bevel pinion 31 mounted rigidly upon a shaft 32. This shaft 32 extends through a washer 33 and through a bearing 34, this bearing being mounted upon an arm 35 and integral with the same. The arm 35 is provided with two bearings 36, 36*;7 theseparts being carried b the bracket 2 and preferably integral t erewith. Extending through these bearings is a shaft 37 of a form shown more particularly in Fig. 3. This shaft carries a pinion 38 secured rigidly upon it .and which meshes with a rack 39, the latter having a longitudinal form and being carried by the tubular member 17.

Mounted loosely upon the shaft 37 is a clutch wheel 40 provided with teeth 41 so arranged as to serve the purpose of a gear wheel. Meshing with this gear wheel and located below it is another gear wheel 42 which is mounted rigidly upon the shaft 32. The clutch wheel 40 is provided with a frlction surface 43 of annular form; and disposed adjacent this friction. surface are a pair of clutch shoes 44 carried on the outer ends of a pair of arms 45. Pivotally connected to these arms are a pair of toggle arms 46, the latter being also pivotally connected to a collar 47 secured rigidly upon the. shaft 37 Mounted upon the shaft 37 is a sleeve 48 provided with a'slot 49 through which extends a pin 50 carried by the shaft 37, thus the sleeve 48 is revoluble with the shaft 37 and has a limited amount of play relatively thereto.

Encircling the sleeve 48 is a spiral spring 51 which engages the bearing 36 and also engages awasher 52 so as to brace this washer constantly against a collar 53 to which the arms 45 are pivotally connected, as indicated in Fig. 3. A brace 54 extends from the arm 35 to another arm 36, the latter supporting the shaft 24. The sleeve 48 carries a milled head 56 having the proximate form of a diskand through which the shaft 37 extends. Mounted rigidly upon one end of the shaft 37 is a milled button 57, and

adjacent this button is a slot 58 in the shaft 37. A latch 59 extends through the button 57 and is pivotally mounted therein. Within the slot 58 is a leaf spring 60 which engages the latch 59.

The shaft 37 has no longitudinal movement, but the sleeve 48 may be moved along the shaft and, thus, is movable relative'to the bearing 36. The operator, by grasping the milled head 56 and movingit to the right according to Fig. 3, may cause the milled head to pass over an adjacent end portion of the latch 59 so that this portion of the latch slides into a notch 61 with which the milled head 56 is provided. Thus, the sleeve 48 is held at the limit of its travel to the right, according to Fig. 3, so long as the latch 59 maintains the position it thus assumes. If, however, the operator grasps the latch 59 and tilts it slightly, he disengages it from the milled head 61. This done, the tension of the spring 51 forces the sleeve 48 to the limit of it's travel to the left, according to Fig. 3, that is, until the friction shoes 44 are brought into firm engagement with the friction surface 43 of the clutch Wheel 40.

When the parts are in the position just described, that is, when the friction shoes 44 are in engagement with the friction surface 43, all of the gearing shown in Fig. 3 is under the control of the gear 23 which is turned because of its engagement with the rack 22; hence, the telescopic tubular section 17 is drawn to the right, according to F ig'. 2, as the reproducer 18 moves inwardly from the outer edge of the record disk toward the center thereof. When, however, the milled head 56 is engaged by the latch 59 so that the sleeve 48 is held fixedly at its extreme position to the right, according to Fig. 3, so that the friction shoes 44 do not engage the friction surface 43, the gearing is, of course,

disconnected. As a result, the movements of the gear wheel 23 have for the time being no effect upon the position of the tubular member 17 With the parts in this condition, the tone arm may be swung inwardly or outwardly and the machine played in any desired manner without causing any difference in the relative lengths of the two members of the bifurcated tone arm.

The operation of my device is as follows, the parts being assembled and arranged as above described, the device is ready for use.

If the operator does not wish to use my attachment for the purpose of suppressing the undesirable sounds above described, he merely grasps the knurled head 56 and pulls it to the right, accordin to Fig. 3, until it engages the latch 59. e then operates the machine in the usual or any desired manner.

If, however, he desires to suppress the undesirable noises mentioned, he shifts the latch 59 and thus releases from its control the knurled head 56. The tension of the spring 51 thereupon throws the friction shoes 44 into engagement with the inner friction surfaces 43 and, for the time being, the annular tubular member 17 has a slow traveling movement to the right, according to Fig. 2, so long as the reproducer is traveling slowly inward during the operation of the machine. This travel of the member 17 causes one member of the bifurcated tone arm to become slightly lon er than the other arm. That is to say as t e re-producer 18 moves toward the center of the disk the sleeve 17 is moved toward the re-producer, or in other words becomes U-shaped, such being the case the entire length of the tubular member including the section 17 becomes elongated. The result of this is that the undesirable hissing sounds, due to the mechanical scratching and rotating of the stylus upon the surface of the record disk, are caused to interfere with each other, that is to say, the sounds passing through one member of the tone arm are brought into interference with the similar sounds passing through the other member of the tone arm, the result being that in so far as these undesirable sounds are concerned the net result is one of virtual silence. In this manner the clarity of the articulation and musical tones made by the instrument are greatly improved.

The parts may be restored to normal position, just after a record has been played, by disconnecting the sleeve 48 from the latch 59, as above suggested, and merely swinging the tone arm back in the usual or any desired manner.

I designate my improvement as a silencer. In order to operate the silencer, I disengage the clutch, swing the tone arm so as to place the needle on the outer edge of the record, and then by turning the shaft 37 to make a separate adjustment for each record, owing to the varying pitch of the records themselves. Experience shows that the needle sounds for one record are shrill and for another comparatively low. Each record has, thus, a distinctive tone, meaning thereby that it sets up a different wave length, of which the undesirable needle sounds are the result.

My device is applicable to commercial dictating machines. In some instances, the gearing may be dispensed with. As a rule, in cylinder machines, only one adjustment 1s necessary.

I do not limit myself to the precise mechanism shown, as variations may be made therein without departing from the spirit of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is as follows:

1. A device of the character described comprising a tone arm provided with a tubular sound passage having a constant length, and further provided with another tubular sound passage having a variable length, and mechanism controllable by the movement of the phonograph for varying the length of said second-mentioned tubular member.

2. A phonographic attachment comprising a plurality of tubular members each serving as a sound passage and merging to gether, gearing, and mechanism propelled by movements of the phonograph for varying the length of one of said tubular members relatively to the other.

3. An attachment for a phonograph comprising a sound passage provided with means for connecting it with the reproducer of a phonograph, and mechanism connected with said reproducer and controllable by movements thereof for varying the length of said sound passage.

4. In a talking machine, the combination of a frame, a tone arm mounted thereupon provided with a sound passage for the purpose of transmitting sounds lengthwise of the arm, mechanism normally connected with the working mechanism of the phonograph and controllable thereby for varying the length of said sound passage, and means operable by hand for disconnecting the said first mentioned mechanism from said working mechanism so as to prevent variation in the length of said sound passage while the phonograph is in action.

DENNIS MONEILL. 

